please help me with the following:
The methanol production process is operated at 250 - 300 ºC & @ pressures of 50 - 100 atmospheres in the presence of a copperbased catalyst.
Comment on whether these operating conditions, 250 - 300 ºC & 50 - 100 atmospheres, are consistent with the aims of achieving a high equilibrium yield of methanol & a high rate of production, noting any potential conflicts in realizing both these aims. Explain the role of the copper-based catalyst, noting how its presence helps to address
any conflicts you have identified and the impact this may have on the overall costs of the production process.
You need to know or be able to find the equilibrium constant for the production of methanol. Remember that rates increase with T and that increasing P favors the side of the reaction with fewer mols of gas.
Is this the equilibrium constant?
CO(g)+2H2(g)<-->CH3OH(g)delta H = -90kj
If so, where do i go from here?
No, but it's the reaction you need to answer the question. You need to read your text and/or notes about the effect of temperature on the rate of a reaction. From a knowledge that rate is increased with increasing T, you know T should be high in order to increase the rate. BUT, this is an exothermic reaction, meaning that heat is given off during the reaction (delta H = -90 kJ--- a negative number tells you that), so increasing T will drive the equilibrium conditions to the left. That will decrease the yield. That is what the problem means when it says "noting any potential conflicts" etc. Increasing pressure will drive the equilibrium to the right (for a gaseous reaction, increasing P will make the reaction shift to the side with fewer moles---there are 3 mols gas on the left and just 1 on the right; therefore, it will shift to the right which increases yield). So you need to raise T to increase rate but not get it too too high for the higher T goes the less the yield. Part of that can be offset by increasing P. You need to put this into your own words as well as address the effect of a catalyst. A catalyst will help increase the speed with which the reaction goes so that will offset, to some degree, the effect of T, also. I hope this helps
To determine whether the operating conditions of 250-300 ºC and 50-100 atmospheres are consistent with achieving a high equilibrium yield of methanol and a high rate of production, we need to analyze the effect of temperature and pressure on the reaction.
The given reaction for methanol production is:
CO(g) + 2H2(g) ↔ CH3OH(g), with ΔH = -90 kJ
First, let's consider the effect of temperature. Increasing the temperature generally increases the rate of a reaction. However, this particular reaction is exothermic, which means it releases heat. In exothermic reactions, increasing the temperature will shift the equilibrium towards the reactants, decreasing the yield of methanol. Therefore, in order to achieve a high equilibrium yield, the temperature must be carefully controlled to balance the rate and yield.
Next, let's look at the effect of pressure. Increasing the pressure generally favors the side of the reaction with fewer moles of gas. In this case, there are three moles of gas on the left side (CO and 2H2) and one mole of gas on the right side (CH3OH). Thus, increasing the pressure will shift the equilibrium towards the right, increasing the yield of methanol. Therefore, higher pressures are favorable for achieving a high equilibrium yield.
Now, let's consider the role of the copper-based catalyst. A catalyst is a substance that speeds up the reaction without being consumed. In the case of methanol production, the copper-based catalyst enhances the rate of the reaction. By providing an alternative reaction pathway with lower activation energy, the catalyst allows the reaction to occur more quickly. This means that even at lower temperatures, the rate of methanol production can be increased. Therefore, the presence of the copper-based catalyst helps to address the conflict between temperature and yield. It allows for a higher rate of production at lower temperatures, mitigating the decrease in yield caused by the exothermic nature of the reaction.
In terms of the overall costs of the production process, the presence of the copper-based catalyst can have a positive impact. By accelerating the reaction rate, the production process can be completed more quickly, leading to higher throughput and potentially reducing costs associated with longer reaction times. However, the cost of the catalyst itself needs to be considered in the overall cost analysis.
In summary, the operating conditions of 250-300 ºC and 50-100 atmospheres are consistent with achieving a high equilibrium yield of methanol and a high rate of production. The temperature needs to be carefully controlled to balance the rate and yield, while higher pressure favors a higher yield. The presence of a copper-based catalyst helps to address the conflict between temperature and yield by increasing the rate of production, even at lower temperatures. This can have a positive impact on the overall costs of the production process, but the cost of the catalyst itself should be considered.